Indicators of general health
The crude protein concentration % can vary in working bees from 21 to 67%.
It is important to maintain the workers with a crude protein concentration above 40%
If the protein concentration falls below 40% the lifespan of the workers will fall from the normal 46-50 days to 20 to 26 days.
If the protein concentration falls below 30% the bees become very susceptible to European Foul Brood (Melissococcus plutonius) and Nosema (Nosema apris and Nosema ceranae). This is particularly important check in the Autumn, as bees with low protein concentration will generally fail to overwinter.